Sinema holds a 0.1-point lead with votes rolling in from Maricopa County, according to new numbers from the Arizona secretary of state's website.

The tally marks a shift from McSally's initial 1-point lead as of earlier on Thursday, when the GOP congresswoman was up by 17,073 votes.

An Arizona source told The Hill that the latest numbers are roughly 150,000 votes from Maricopa County, with another 345,000 outstanding votes still left from that county, which includes the capital of Phoenix. The Maricopa County recorder announced that the next update will be posted on Friday at 5 p.m. local time.